The present invention relates generally to handheld medical devices for precisely delivering energy into a human body, and more particularly to handheld medical devices and related systems having an actuation assembly for controlling the position/orientation of a directional energy applicator in at least two planes. The position/orientation control provided can be especially beneficial when used in a medical ultrasound therapy head that is used for non-invasive therapies.
A general problem in the application of high intensity focused ultrasound (HIFU) for therapeutic purposes is that it is often necessary to hold the therapeutic means stationary for some significant amount of time over the tissue to be treated. Alternatively, it may be necessary to scan the therapy beam at a slow, constant rate through the tissue to be treated. Both of these requirements present a barrier to the use of hand-held therapeutic devices, as it is often difficult or impossible for a person to either hold the device steady, or to scan at an acceptably slow and steady rate for the desired therapeutic effect.
A HIFU procedure may require that the ultrasound beam be scanned over the treatment volume at a constant rate (e.g., 5 mm/sec+/−1 mm/sec) to achieve the desired therapeutic effect. Additionally, the treatment volume must be scanned so that there is never more than a 2 mm spacing between adjacent focal lines of treatment. These requirements are beyond the capabilities of most human beings. The solution in the past has been to incorporate a computer controlled motion device rigidly mounted to something that is stationary with respect to the patient (e.g., the floor, wall or bed). Such a device is either absolutely stationary, or is able to scan at a precise rate in a precise pattern without any human intervention. Such an arrangement has the disadvantages of size and bulk, complexity and reliability of the overall device.
Thus there remains a need in the art for a HIFU applicator that can be easily manipulated by a user while still providing reliable and uniform treatment.
There is also a need for a HIFU transducer that can keep track of the tissue volumes treated so as to prevent re-treatment of those same volumes.
There is still further a need for a therapy device that can assist the operator in identifying regions of tissue to be treated.